I recently encoded Atari Teenage Riot's album "Burn, Berlin, Burn!" with Lame 3.90.2 and --alt-preset extreme. Many of the tracks ended up with curiously low bitrates, including one at 143. Is this something to be worried about? I haven't been able to test yet on good equipment, but can APX produce bitrates that low without compromising quality?

which program are you using to find out the average bitrate?
I know that EncStop by default only scan the first 1000 frames of an mp3 file. Maybe if there is a lot of silence/easily encoded music in the beginning of the song that could be the reason of a reported low bitrate. If you are using encspot do a full scan of the files.

If it was to have the same bitrate it would be called CBR, if it was to have an average bitrate of X, it would be ABR x.
But it is none of them, it's VBR.

Of course there could be a potential problem where it would fail, but just seeing a low average bitrate should give you more glory than worry (more space for you to be used).

Again, aps is said to create files about 200kbps. Sometimes, it creates files up to 260kbps or even more. At the same time, files with lower bitrate are perfectly understandable, because if not, how would 200kbps be the average?

Originally posted by [JAZ] I wonder how people can't understand what VBR is.

APX typically produces bitrates ~250 so 143 is WELL below that range. No need to be a jackass. I was just wondering if it was possible that APX could be failing or is 148 within the realm of possibility on a song with no silence?

Originally posted by john33 An upper bitrate of 192 is certainly far lower than would be expected.

I don't have EncSpot Pro so I can't tell exactly how many frames, but there are some 224, 256, 320; just not many.

[b]maciey, the files are not mono, so do you mean if the two tracks match up exactly? Will EAC let me do a compare like this on the original WAV?

Now that I look at it, on the tracks where bitrate is low, EncSpot shows 99.X% ms-type Joint Stereo. On tracks where bitrate is higher, it is more evenly distributed between ms-type and ss-type. Could this because of what maciey is saying?